Cross-domain network assurance

ABSTRACT

Systems, methods, and computer-readable media for providing cross-domain assurance for networks in different network domains. In some embodiments, a method can include collecting first fabric data for a first network in a first network domain and second fabric data for a second network in a second network domain. The second fabric data for the second network can be normalized based on the first network domain to create normalized second fabric data. The first fabric data can then be correlated with the normalized second fabric data to create correlated fabric data. Subsequently, assurance can be provided across the first network in the first network domain and the second network in the second network domain using the correlated fabric data.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation and claims priority to U.S. Non-Provisional patent application Ser. No. 16/002,981, filed on Jun. 7, 2018, the full disclosure of which is hereby expressly incorporated by reference in its entirety.

TECHNICAL FIELD

The present technology pertains to providing network assurance and in particular to providing network assurance across networks in different network domains. In particular, each domain may use a discrete set of technologies, protocols to implement forwarding between elements and endpoints that reside on these elements. The network domains may also implement policy between network elements themselves, or between endpoints attached to said network elements using a discrete set of technologies.

BACKGROUND

Software-defined networks (SDNs) have been developed in order to improve performance in networks and provide greater control in managing networks. SDNs can decouple network control and forwarding functions to create programmable network control. In turn, this can abstract an underlying network infrastructure from applications and network services. This can allow for easy control and configuring of network environments by network administrators.

Sensors and network tools can be utilized in SDNs to provide assurance in the SDNs. Specifically, sensors can be implemented in an SDN to gather data for the SDN and network tools can model operation and behaviors of the SDN based on data gathered by the sensor. Subsequently, events can be generated for the SDN using the gathered data and models in order to provide assurance in the SDN. Such sensors and network tools can provide assurance on a per-SDN basis. Specifically, such sensors and network tools can provide assurance for a network in a specific network domain without respect to communications and interactions between the network and other networks in different network domains. This is problematic, as network traffic often times originates from one network domain and extends into another network in a different network domain. However, as assurance is only provided on a per-network domain basis, the network traffic is only assured with respect to a specific network that a portion of the network traffic passes through. More specifically, the network traffic is not assured across multiple networks, e.g. SDNs, in multiple domains that the network traffic ultimately spans across. There therefore exist needs for normalizing forwarding, policy and other semantics in each SDN and providing assurance across multiple networks, e.g. SDNs, across different network domains.

Further, in typical SDNs, policies can be configured which ultimately deploys rules in switches to enforce control on underlying traffic. In particular, policies can be deployed to controllers and/or identity services engines where the policies can be used to deploy rules for controlling underlying traffic. As part of providing assurance, such policies can be modeled to ensure that desired, e.g. intent-based, traffic control is actually being enforced in the SDN. As assurance is provided on a per-network basis, policy checks are performed irrespective of policies that exist in networks in different domains. Specifically, SDNs in different network domains that are communicating with each other can have conflicting or otherwise incompatible policies. In turn, providing assurance on a per-network basis can lead to failures in recognizing the conflicts between the policies. There therefore exist needs for providing policy assurance across multiple networks, e.g. SDNs, in different network domains.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which the above-recited and other advantages and features of the disclosure can be obtained, a more particular description of the principles briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only exemplary embodiments of the disclosure and are not therefore to be considered to be limiting of its scope, the principles herein are described and explained with additional specificity and detail through the use of the accompanying drawings in which:

FIGS. 1A and 1B illustrate example network environments;

FIG. 2A illustrates an example object model for a network;

FIG. 2B illustrates an example object model for a tenant object in the example object model from FIG. 2A;

FIG. 2C illustrates an example association of various objects in the example object model from FIG. 2A;

FIG. 2D illustrates a schematic diagram of example models for implementing the example object model from FIG. 2A;

FIG. 3A illustrates an example network assurance appliance;

FIG. 3B illustrates an example system for network assurance;

FIG. 3C illustrates a schematic diagram of an example system for static policy analysis in a network.

FIG. 4 illustrates an example method embodiment for network assurance;

FIG. 5 illustrates an environment for providing cross-domain assurance;

FIG. 6 illustrates a flowchart for an example method of providing cross-domain assurance;

FIG. 7 shows a screen shot of an interface showing allowed cross-domain access as part of providing cross-domain assurance;

FIG. 8 illustrates an example network device in accordance with various embodiments; and

FIG. 9 illustrates an example computing device in accordance with various embodiments.

DESCRIPTION OF EXAMPLE EMBODIMENTS

Various embodiments of the disclosure are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the disclosure. Thus, the following description and drawings are illustrative and are not to be construed as limiting. Numerous specific details are described to provide a thorough understanding of the disclosure. However, in certain instances, well-known or conventional details are not described in order to avoid obscuring the description. References to one or an embodiment in the present disclosure can be references to the same embodiment or any embodiment; and, such references mean at least one of the embodiments.

Reference to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others.

The terms used in this specification generally have their ordinary meanings in the art, within the context of the disclosure, and in the specific context where each term is used. Alternative language and synonyms may be used for any one or more of the terms discussed herein, and no special significance should be placed upon whether or not a term is elaborated or discussed herein. In some cases, synonyms for certain terms are provided. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only, and is not intended to further limit the scope and meaning of the disclosure or of any example term. Likewise, the disclosure is not limited to various embodiments given in this specification.

Without intent to limit the scope of the disclosure, examples of instruments, apparatus, methods and their related results according to the embodiments of the present disclosure are given below. Note that titles or subtitles may be used in the examples for convenience of a reader, which in no way should limit the scope of the disclosure. Unless otherwise defined, technical and scientific terms used herein have the meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In the case of conflict, the present document, including definitions will control.

Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or can be learned by practice of the herein disclosed principles. The features and advantages of the disclosure can be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the disclosure will become more fully apparent from the following description and appended claims, or can be learned by the practice of the principles set forth herein.

Overview

A method can include collecting first fabric data for a first network in a first network domain and second fabric data for a second network in a second network domain. The second fabric data for the second network can be normalized based on the first network domain to create normalized second fabric data. Further, the first fabric data can be correlated with the normalized second fabric data to create correlated fabric data. Subsequently, assurance can be provided across the first network in the first network domain and the second network in the second network domain using the correlated fabric data.

A system can collect first fabric data for a first network in a first network domain and second fabric data for a second network in a second network domain. The system can also normalize the second fabric data for the second network in the second network domain based on the first network domain to create normalized second fabric data. Further, the system can correlate the first fabric data with the normalized second fabric data to create correlated fabric data to provide assurance across the first network in the first network domain and the second network in the second network domain.

A system can query identity management platforms to obtain mappings of endpoint(s) to security group(s).

A system can provide a framework to map business level intent (E.g. PCI servers should not talk to non-PCI endpoints) using a tagging mechanism by allowing for mapping of operator or administrator defined tags to security group(s) obtained from the identity management platform or a configuration management database (CMDB). [E.g. The assurance system may let the operator define a tag of “PCI servers” for all endpoints in a subnet range (like 10.1.1.0/24) or all security groups with a certain name (like security group name contains “prod_web_”]

A system can collect first fabric data for a first network in a first network domain and second fabric data for a second network in a second network domain. The first network domain and the second network domain can be different network domain types. The system can normalize the second fabric data for the second network in the second network domain based on the first network domain to create normalized second fabric data. The system can then correlate the first fabric data with the normalized second fabric data to create correlated fabric data. Subsequently, the system can provide assurance across the first network in the first network domain and the second network in the second network domain using the correlated fabric data.

A system can cross-reference information from the identity management platform with normalized information from both network domains to determine the sanctity of this data across the identity management system and both network domains is consistent.

A system can provide alerting to operator(s) and administrator(s) of the identity management system and of the network domain(s) with specific corrective actions in each domain to be taken to resolve any consistency issues.

A system can provide the ability for end users to consume this data using simple query terms like ‘Can A talk to B’ [where A is an endpoint in the datacenter domain, B is an endpoint in a different SDN domain] without having to understand, extrapolate and interpret the intricacies of each SDN domain.

A system can provide insight into exact semantics (e.g. forwarding, policy, etc.) that may be causing communication (or lack thereof) between two or more endpoints in each domain and suggest specific steps to be followed by the operator(s) or administrator(s) of each domain to either permit or restrict traffic flow between these endpoints

A system can consume business level intent (e.g. PCI servers should not talk to non-PCI users). Glean mappings of PCI, non-PCI endpoints from a policy, posture verification engine. Perform tagging of these endpoints based on user defined policies. Perform cross-domain co-relation across the identity management system (e.g. Cisco ISE) and various SDN domains (E.g. Datacenter, WAN, Campus) when intent is violated and provide a notification to the operator(s) and administrator(s) of relevant domains on business level intent being violated.

EXAMPLE EMBODIMENTS

The disclosed technology addresses the need in the art for providing network assurance. The present technology involves system, methods, and computer-readable media for providing network assurance across networks in different network domains. The present technology will be described in the following disclosure as follows.

The discussion begins with an introductory discussion of network assurance and a description of example computing environments, as illustrated in FIGS. 1A and 1B. A discussion of network models for network assurance, as shown in FIGS. 2A through 2D, and network assurance systems and methods, as shown in FIGS. 3A-C and 4 will then follow. The discussion continues with a description and examples of providing cross-domain assurance, as shown in FIGS. 5-7. The discussion concludes with a description of an example network device, as illustrated in FIG. 8, and an example computing device, as illustrated in FIG. 9, including example hardware components suitable for hosting software applications and performing computing operations. The disclosure now turns to an introductory discussion of network assurance.

Network assurance is the guarantee or determination that the network is behaving as intended by the network operator and has been configured properly (e.g., the network is doing network and individual network elements (e.g., switches, routers, applications, resources, etc.). However, often times, the configurations, policies, etc., defined by a network operator are incorrect or not accurately reflected in the actual behavior of the network. For example, a network operator specifies a configuration A for one or more types of traffic but later finds out that the network is actually applying configuration B to that traffic or otherwise processing that traffic in a manner that is inconsistent with configuration A. This can be a result of many different causes, such as hardware errors, software bugs, varying priorities, configuration conflicts, misconfiguration of one or more settings, improper rule rendering by devices, unexpected errors or events, software upgrades, configuration changes, failures, etc. As another example, a network operator implements configuration C but one or more other configurations result in the network behaving in a manner that is inconsistent with the intent reflected by the implementation of configuration C. For example, such a situation can result when configuration C conflicts with other configurations in the network.

The approaches herein can provide network assurance by modeling various aspects of the network and/or performing consistency checks as well as other network assurance checks. The network assurance approaches herein can be implemented in various types of networks, including a private network, such as a local area network (LAN); an enterprise network; a standalone or traditional network, such as a data center network; a network including a physical or underlay layer and a logical or overlay layer, such as a VXLAN or SDN (e.g., Application Centric Infrastructure (ACI), Amazon AWS VPCs, VXLAN EVPN based datacenter fabrics, VMware NSX networks); etc.

Network models can be constructed for a network and implemented for network assurance. A network model can provide a representation of one or more aspects of a network, including, without limitation the network's policies, configurations, requirements, security, routing, topology, applications, hardware, filters, contracts, access control lists, infrastructure, etc. As will be further explained below, different types of models can be generated for a network.

Such models can be implemented to ensure that the behavior of the network will be consistent (or is consistent) with the intended behavior reflected through specific configurations (e.g., policies, settings, definitions, etc.) implemented by the network operator. Unlike traditional network monitoring, which involves sending and analyzing data packets and observing network behavior, network assurance can be performed through modeling without necessarily ingesting packet data or monitoring traffic or network behavior. This can result in foresight, insight, and hindsight: problems can be prevented before they occur, identified when they occur, and fixed immediately after they occur.

Thus, network assurance can involve modeling properties of the network to deterministically predict the behavior of the network. The network can be determined to be healthy if the model(s) indicate proper behavior (e.g., no inconsistencies, conflicts, errors, etc.). The network can be determined to be functional, but not fully healthy, if the modeling indicates proper behavior but some inconsistencies. The network can be determined to be non-functional and not healthy if the modeling indicates improper behavior and errors. If inconsistencies or errors are detected by the modeling, a detailed analysis of the corresponding model(s) can allow one or more underlying or root problems to be identified with great accuracy.

The modeling can consume numerous types of smart events which model a large amount of behavioral aspects of the network. Smart events can impact various aspects of the network, such as underlay services, overlay services, tenant connectivity, tenant security, tenant endpoint (EP) mobility, tenant policy, tenant routing, resources, etc. Further, the modeling can consumer numerous types of smart events which model a large amount of behavioral aspects across networks, e.g. as part of providing cross-domain assurance for the networks.

Having described various aspects of network assurance, the disclosure now turns to a discussion of example network environments for network assurance.

FIG. 1A illustrates a diagram of an example Network Environment 100, such as a data center. The Network Environment 100 can include a Fabric 120 which can represent the physical layer or infrastructure (e.g., underlay) of the Network Environment 100. Fabric 120 can include Spines 102 (e.g., spine routers or switches) and Leafs 104 (e.g., leaf routers or switches) which can be interconnected for routing or switching traffic in the Fabric 120. Spines 102 can interconnect Leafs 104 in the Fabric 120, and Leafs 104 can connect the Fabric 120 to an overlay or logical portion of the Network Environment 100, which can include application services, servers, virtual machines, containers, endpoints, etc. Thus, network connectivity in the Fabric 120 can flow from Spines 102 to Leafs 104, and vice versa. The interconnections between Leafs 104 and Spines 102 can be redundant (e.g., multiple interconnections) to avoid a failure in routing. In some embodiments, Leafs 104 and Spines 102 can be fully connected, such that any given Leaf is connected to each of the Spines 102, and any given Spine is connected to each of the Leafs 104. Leafs 104 can be, for example, top-of-rack (“ToR”) switches, aggregation switches, gateways, ingress and/or egress switches, provider edge devices, and/or any other type of routing or switching device.

Leafs 104 can be responsible for routing and/or bridging tenant or customer packets and applying network policies or rules. Network policies and rules can be driven by one or more Controllers 116, and/or implemented or enforced by one or more devices, such as Leafs 104. Leafs 104 can connect other elements to the Fabric 120. For example, Leafs 104 can connect Servers 106, Hypervisors 108, Virtual Machines (VMs) 110, Applications 112, Network Device 114, etc., with Fabric 120. Such elements can reside in one or more logical or virtual layers or networks, such as an overlay network. In some cases, Leafs 104 can encapsulate and decapsulate packets to and from such elements (e.g., Servers 106) in order to enable communications throughout Network Environment 100 and Fabric 120. Leafs 104 can also provide any other devices, services, tenants, or workloads with access to Fabric 120. In some cases, Servers 106 connected to Leafs 104 can similarly encapsulate and decapsulate packets to and from Leafs 104. For example, Servers 106 can include one or more virtual switches or routers or tunnel endpoints for tunneling packets between an overlay or logical layer hosted by, or connected to, Servers 106 and an underlay layer represented by Fabric 120 and accessed via Leafs 104.

Applications 112 can include software applications, services, containers, appliances, functions, service chains, etc. For example, Applications 112 can include a firewall, a database, a CDN server, an IDS/IPS, a deep packet inspection service, a message router, a virtual switch, etc. An application from Applications 112 can be distributed, chained, or hosted by multiple endpoints (e.g., Servers 106, VMs 110, etc.), or may run or execute entirely from a single endpoint.

VMs 110 can be virtual machines hosted by Hypervisors 108 or virtual machine managers running on Servers 106. VMs 110 can include workloads running on a guest operating system on a respective server. Hypervisors 108 can provide a layer of software, firmware, and/or hardware that creates, manages, and/or runs the VMs 110. Hypervisors 108 can allow VMs 110 to share hardware resources on Servers 106, and the hardware resources on Servers 106 to appear as multiple, separate hardware platforms. Moreover, Hypervisors 108 on Servers 106 can host one or more VMs 110.

In some cases, VMs 110 and/or Hypervisors 108 can be migrated to other Servers 106. Servers 106 can similarly be migrated to other locations in Network Environment 100. For example, a server connected to a specific leaf can be changed to connect to a different or additional leaf. Such configuration or deployment changes can involve modifications to settings, configurations and policies that are applied to the resources being migrated as well as other network components.

In some cases, one or more Servers 106, Hypervisors 108, and/or VMs 110 can represent or reside in a tenant or customer space. Tenant space can include workloads, services, applications, devices, networks, and/or resources that are associated with one or more clients or subscribers. Accordingly, traffic in Network Environment 100 can be routed based on specific tenant policies, spaces, agreements, configurations, etc. Moreover, addressing can vary between one or more tenants. In some configurations, tenant spaces can be divided into logical segments and/or networks and separated from logical segments and/or networks associated with other tenants. Addressing, policy, security and configuration information between tenants can be managed by Controllers 116, Servers 106, Leafs 104, etc.

Configurations in Network Environment 100 can be implemented at a logical level, a hardware level (e.g., physical), and/or both. For example, configurations can be implemented at a logical and/or hardware level based on endpoint or resource attributes, such as endpoint types and/or application groups or profiles, through a software-defined network (SDN) framework (e.g., Application-Centric Infrastructure (ACI) or VMWARE NSX). To illustrate, one or more administrators can define configurations at a logical level (e.g., application or software level) through Controllers 116, which can implement or propagate such configurations through Network Environment 100. In some examples, Controllers 116 can be Application Policy Infrastructure Controllers (APICs) in an ACI framework. In other examples, Controllers 116 can be one or more management components for associated with other SDN solutions, such as NSX Managers.

Such configurations can define rules, policies, priorities, protocols, attributes, objects, etc., for routing and/or classifying traffic in Network Environment 100. For example, such configurations can define attributes and objects for classifying and processing traffic based on Endpoint Groups (EPGs), Security Groups (SGs), VM types, bridge domains (BDs), virtual routing and forwarding instances (VRFs), tenants, priorities, firewall rules, etc. Other example network objects and configurations are further described below. Traffic policies and rules can be enforced based on tags, attributes, or other characteristics of the traffic, such as protocols associated with the traffic, EPGs associated with the traffic, SGs associated with the traffic, network address information associated with the traffic, etc. Such policies and rules can be enforced by one or more elements in Network Environment 100, such as Leafs 104, Servers 106, Hypervisors 108, Controllers 116, etc. As previously explained, Network Environment 100 can be configured according to one or more particular software-defined network (SDN) solutions, such as CISCO ACI or VMWARE NSX. These example SDN solutions are briefly described below.

ACI can provide an application-centric or policy-based solution through scalable distributed enforcement. ACI supports integration of physical and virtual environments under a declarative configuration model for networks, servers, services, security, requirements, etc. For example, the ACI framework implements EPGs, which can include a collection of endpoints or applications that share common configuration requirements, such as security, QoS, services, etc. Endpoints can be virtual/logical or physical devices, such as VMs, containers, hosts, or physical servers that are connected to Network Environment 100. Endpoints can have one or more attributes such as a VM name, guest OS name, a security tag, application profile, etc. Application configurations can be applied between EPGs, instead of endpoints directly, in the form of contracts. Leafs 104 can classify incoming traffic into different EPGs. The classification can be based on, for example, a network segment identifier such as a VLAN ID, VXLAN Network Identifier (VNID), NVGRE Virtual Subnet Identifier (VSID), MAC address, IP address, etc.

In some cases, classification in the ACI fabric can be implemented by Application Virtual Switches (AVS), which can run on a host, such as a server or switch. For example, an AVS can classify traffic based on specified attributes, and tag packets of different attribute EPGs with different identifiers, such as network segment identifiers (e.g., VLAN ID). Finally, Leafs 104 can tie packets with their attribute EPGs based on their identifiers and enforce policies, which can be implemented and/or managed by one or more Controllers 116. Leaf 104 can classify to which EPG the traffic from a host belongs and enforce policies accordingly.

Another example SDN solution is based on VMWARE NSX. With VMWARE NSX, hosts can run a distributed firewall (DFW) which can classify and process traffic. Consider a case where three types of VMs, namely, application, database and web VMs, are put into a single layer-2 network segment. Traffic protection can be provided within the network segment based on the VM type. For example, HTTP traffic can be allowed among web VMs, and disallowed between a web VM and an application or database VM. To classify traffic and implement policies, VMWARE NSX can implement security groups, which can be used to group the specific VMs (e.g., web VMs, application VMs, database VMs). DFW rules can be configured to implement policies for the specific security groups. To illustrate, in the context of the previous example, DFW rules can be configured to block HTTP traffic between web, application, and database security groups.

Returning now to FIG. 1A, Network Environment 100 can deploy different hosts via Leafs 104, Servers 106, Hypervisors 108, VMs 110, Applications 112, and Controllers 116, such as VMWARE ESXi hosts, WINDOWS HYPER-V hosts, bare metal physical hosts, etc. Network Environment 100 may interoperate with a variety of Hypervisors 108, Servers 106 (e.g., physical and/or virtual servers), SDN orchestration platforms, etc. Network Environment 100 may implement a declarative model to allow its integration with application design and holistic network policy.

Controllers 116 can provide centralized access to fabric information, application configuration, resource configuration, application-level configuration modeling for a software-defined network (SDN) infrastructure, integration with management systems or servers, etc. Controllers 116 can form a control plane that interfaces with an application plane via northbound APIs and a data plane via southbound APIs.

As previously noted, Controllers 116 can define and manage application-level model(s) for configurations in Network Environment 100. In some cases, application or device configurations can also be managed and/or defined by other components in the network. For example, a hypervisor or virtual appliance, such as a VM or container, can run a server or management tool to manage software and services in Network Environment 100, including configurations and settings for virtual appliances.

As illustrated above, Network Environment 100 can include one or more different types of SDN solutions, hosts, etc. For the sake of clarity and explanation purposes, various examples in the disclosure will be described with reference to an ACI framework, and Controllers 116 may be interchangeably referenced as controllers, APICs, or APIC controllers. However, it should be noted that the technologies and concepts herein are not limited to ACI solutions and may be implemented in other architectures and scenarios, including other SDN solutions as well as other types of networks which may not deploy an SDN solution.

Further, as referenced herein, the term “hosts” can refer to Servers 106 (e.g., physical or logical), Hypervisors 108, VMs 110, containers (e.g., Applications 112), etc., and can run or include any type of server or application solution. Non-limiting examples of “hosts” can include virtual switches or routers, such as distributed virtual switches (DVS), application virtual switches (AVS), vector packet processing (VPP) switches; VCENTER and NSX MANAGERS; bare metal physical hosts; HYPER-V hosts; VMs; DOCKER Containers; etc.

FIG. 1B illustrates another example of Network Environment 100. The Network Environment 100 shown in FIG. 1B can represent a DNA network of an enterprise, e.g. a campus network. In this example, Network Environment 100 includes Endpoints 122 connected to Fabric Edge Nodes 104 in Fabric 120, which are connected to Fabric Border Nodes 102 in Fabric 120. Fabric Border Nodes 102 can connect traditional layer 3 networks or different fabric domains to an enterprise fabric domain. Fabric Edge Nodes 104 lie at the perimeter of the Fabric 120 and can serve as the first points of attachment of policy. For example, Fabric Edge Nodes 104 can admit, encapsulate, decapsulate, and forward traffic from Endpoints 122. Fabric Edge Nodes 104 can connect to Endpoints 122 through an intermediate Layer 2 network, e.g. through a wireless access point.

Endpoints 122 can be physical and/or logical or virtual entities, such as servers, clients, VMs, hypervisors, software containers, applications, resources, network devices, workloads, etc. For example, an Endpoint 122 can be an object that represents a physical device (e.g., server, client, switch, etc.), an application (e.g., web application, database application, etc.), a logical or virtual resource (e.g., a virtual switch, a virtual service appliance, a virtualized network function (VNF), a VM, a service chain, etc.), a container running a software resource (e.g., an application, an appliance, a VNF, a service chain, etc.), storage, a workload or workload engine, etc. Endpoints 122 can have an address (e.g., an identity), a location (e.g., host, network segment, virtual routing and forwarding (VRF) instance, domain, etc.), one or more attributes (e.g., name, type, version, patch level, OS name, OS type, etc.), a tag (e.g., security tag), a profile, etc. Endpoints 122 can also include physical devices in the Network Environment 100, e.g. cameras, sensors, PCs, and laptops.

Endpoints 122 can be associated with respective Security Groups 118. Security Groups 118 can be logical entities containing endpoints (physical and/or logical or virtual) grouped together according to one or more attributes, such as endpoint type (e.g., VM type, workload type, application type, etc.), one or more requirements (e.g., policy requirements, security requirements, QoS requirements, customer requirements, resource requirements, etc.), a resource name (e.g., VM name, application name, etc.), a profile, platform or operating system (OS) characteristics (e.g., OS type or name including guest and/or host OS, etc.), an associated network or tenant, one or more policies, a tag, etc. For example, a security group can be an object representing a collection of endpoints grouped together. To illustrate, Security Group 1 can contain student endpoints, Security Group 2 can contain faculty endpoints, Security Group 3 can contain network administrator endpoints, Logical Group N can contain different student group endpoints, etc. In some examples, Security Groups 118 are EPGs in a SDN environment, e.g. a DNA campus network.

Traffic to and/or from Endpoints 122 can be classified, processed, managed, etc., based on Security Groups 118. For example, Security Groups 118 can be used to classify traffic to or from Endpoints 122, apply policies to traffic to or from Endpoints 122, define relationships between Endpoints 122, define roles of Endpoints 122 (e.g., whether an endpoint consumes or provides a service, etc.), apply rules to traffic to or from Endpoints 122, apply filters or access control lists (ACLs) to traffic to or from Endpoints 122, define communication paths for traffic to or from Endpoints 122, enforce requirements associated with Endpoints 122, implement security and other configurations associated with Endpoints 122, etc.

FIG. 2A illustrates a diagram of an example Management Information Model 200 for an SDN network, such as Network Environment 100. The following discussion of Management Information Model 200 references various terms which shall also be used throughout the disclosure. Accordingly, for clarity, the disclosure shall first provide below a list of terminology, which will be followed by a more detailed discussion of Management Information Model 200.

As used herein, an “Alias” can refer to a changeable name for a given object. Thus, even if the name of an object, once created, cannot be changed, the Alias can be a field that can be changed.

As used herein, the term “Aliasing” can refer to a rule (e.g., contracts, policies, configurations, etc.) that overlaps one or more other rules. For example, Contract 1 defined in a logical model of a network can be said to be aliasing Contract 2 defined in the logical model of the network if Contract 1 overlaps Contract 1. In this example, by aliasing Contract 2, Contract 1 may render Contract 2 redundant or inoperable. For example, if Contract 1 has a higher priority than Contract 2, such aliasing can render Contract 2 redundant based on Contract 1's overlapping and higher priority characteristics.

As used herein, the term “APIC” can refer to one or more controllers (e.g., Controllers 116) in an ACI framework. The APIC can provide a unified point of automation and management, policy programming, application deployment, health monitoring for an ACI multitenant fabric. The APIC can be implemented as a single controller, a distributed controller, or a replicated, synchronized, and/or clustered controller.

As used herein, the term “BDD” can refer to a binary decision tree. A binary decision tree can be a data structure representing functions, such as Boolean functions.

As used herein, the term “BD” can refer to a bridge domain. A bridge domain can be a set of logical ports that share the same flooding or broadcast characteristics. Like a virtual LAN (VLAN), bridge domains can span multiple devices. A bridge domain can be a L2 (Layer 2) construct.

As used herein, a “Consumer” can refer to an endpoint, resource, and/or EPG that consumes a service.

As used herein, a “Context” can refer to an L3 (Layer 3) address domain that allows multiple instances of a routing table to exist and work simultaneously. This increases functionality by allowing network paths to be segmented without using multiple devices. Non-limiting examples of a context or L3 address domain can include a Virtual Routing and Forwarding (VRF) instance, a private network, and so forth.

As used herein, the term “Contract” can refer to rules or configurations that specify what and how communications in a network are conducted (e.g., allowed, denied, filtered, processed, etc.). In an ACI network, contracts can specify how communications between endpoints and/or EPGs take place. In some examples, a contract can provide rules and configurations akin to an Access Control List (ACL).

As used herein, the term “Distinguished Name” (DN) can refer to a unique name that describes an object, such as an MO, and locates its place in Management Information Model 200. In some cases, the DN can be (or equate to) a Fully Qualified Domain Name (FQDN).

As used herein, the term “Endpoint Group” (EPG) can refer to a logical entity or object associated with a collection or group of endpoints as previously described with reference to FIG. 1B.

As used herein, the term “Filter” can refer to a parameter or configuration for allowing communications. For example, in a whitelist model where all communications are blocked by default, a communication must be given explicit permission to prevent such communication from being blocked. A filter can define permission(s) for one or more communications or packets. A filter can thus function similar to an ACL or Firewall rule. In some examples, a filter can be implemented in a packet (e.g., TCP/IP) header field, such as L3 protocol type, L4 (Layer 4) ports, and so on, which is used to allow inbound or outbound communications between endpoints or EPGs, for example.

As used herein, the term “L2 Out” can refer to a bridged connection. A bridged connection can connect two or more segments of the same network so that they can communicate. In an ACI framework, an L2 out can be a bridged (Layer 2) connection between an ACI fabric (e.g., Fabric 120) and an outside Layer 2 network, such as a switch.

As used herein, the term “L3 Out” can refer to a routed connection. A routed Layer 3 connection uses a set of protocols that determine the path that data follows in order to travel across networks from its source to its destination. Routed connections can perform forwarding (e.g., IP forwarding) according to a protocol selected, such as BGP (border gateway protocol), OSPF (Open Shortest Path First), EIGRP (Enhanced Interior Gateway Routing Protocol), etc.

As used herein, the term “Managed Object” (MO) can refer to an abstract representation of objects that are managed in a network (e.g., Network Environment 100). The objects can be concrete objects (e.g., a switch, server, adapter, etc.), or logical objects (e.g., an application profile, an EPG, a fault, etc.). The MOs can be network resources or elements that are managed in the network. For example, in an ACI environment, an MO can include an abstraction of an ACI fabric (e.g., Fabric 120) resource.

As used herein, the term “Management Information Tree” (MIT) can refer to a hierarchical management information tree containing the MOs of a system. For example, in ACI, the MIT contains the MOs of the ACI fabric (e.g., Fabric 120). The MIT can also be referred to as a Management Information Model (MIM), such as Management Information Model 200.

As used herein, the term “Policy” can refer to one or more specifications for controlling some aspect of system or network behavior. For example, a policy can include a named entity that contains specifications for controlling some aspect of system behavior. To illustrate, a Layer 3 Outside Network Policy can contain the BGP protocol to enable BGP routing functions when connecting Fabric 120 to an outside Layer 3 network.

As used herein, the term “Profile” can refer to the configuration details associated with a policy. For example, a profile can include a named entity that contains the configuration details for implementing one or more instances of a policy. To illustrate, a switch node profile for a routing policy can contain the switch-specific configuration details to implement the BGP routing protocol.

As used herein, the term “Provider” refers to an object or entity providing a service. For example, a provider can be an EPG that provides a service.

As used herein, the term “Subject” refers to one or more parameters in a contract for defining communications. For example, in ACI, subjects in a contract can specify what information can be communicated and how. Subjects can function similar to ACLs.

As used herein, the term “Tenant” refers to a unit of isolation in a network. For example, a tenant can be a secure and exclusive virtual computing environment. In ACI, a tenant can be a unit of isolation from a policy perspective, but does not necessarily represent a private network. Indeed, ACI tenants can contain multiple private networks (e.g., VRFs). Tenants can represent a customer in a service provider setting, an organization or domain in an enterprise setting, or just a grouping of policies.

As used herein, the term “VRF” refers to a virtual routing and forwarding instance. The VRF can define a Layer 3 address domain that allows multiple instances of a routing table to exist and work simultaneously. This increases functionality by allowing network paths to be segmented without using multiple devices. Also known as a context or private network.

Having described various terms used herein, the disclosure now returns to a discussion of Management Information Model (MIM) 200 in FIG. 2A. As previously noted, MIM 200 can be a hierarchical management information tree or MIT. Moreover, MIM 200 can be managed and processed by Controllers 116, such as APICs in an ACI. Controllers 116 can enable the control of managed resources by presenting their manageable characteristics as object properties that can be inherited according to the location of the object within the hierarchical structure of the model.

The hierarchical structure of MIM 200 starts with Policy Universe 202 at the top (Root) and contains parent and child nodes 116, 204, 206, 208, 210, 212. Nodes 116, 202, 204, 206, 208, 210, 212 in the tree represent the managed objects (MOs) or groups of objects. Each object in the fabric (e.g., Fabric 120) has a unique distinguished name (DN) that describes the object and locates its place in the tree. The Nodes 116, 202, 204, 206, 208, 210, 212 can include the various MOs, as described below, which contain policies that govern the operation of the system.

Controllers 116

Controllers 116 (e.g., APIC controllers) can provide management, policy programming, application deployment, and health monitoring for Fabric 120.

Node 204

Node 204 includes a tenant container for policies that enable an administrator to exercise domain-based access control. Non-limiting examples of tenants can include:

User tenants defined by the administrator according to the needs of users. They contain policies that govern the operation of resources such as applications, databases, web servers, network-attached storage, virtual machines, and so on.

The common tenant is provided by the system but can be configured by the administrator. It contains policies that govern the operation of resources accessible to all tenants, such as firewalls, load balancers, Layer 4 to Layer 7 services, intrusion detection appliances, and so on.

The infrastructure tenant is provided by the system but can be configured by the administrator. It contains policies that govern the operation of infrastructure resources such as the fabric overlay (e.g., VXLAN). It also enables a fabric provider to selectively deploy resources to one or more user tenants. Infrastructure tenant polices can be configurable by the administrator.

The management tenant is provided by the system but can be configured by the administrator. It contains policies that govern the operation of fabric management functions used for in-band and out-of-band configuration of fabric nodes. The management tenant contains a private out-of-bound address space for the Controller/Fabric internal communications that is outside the fabric data path that provides access through the management port of the switches. The management tenant enables discovery and automation of communications with virtual machine controllers.

Node 206

Node 206 can contain access policies that govern the operation of switch access ports that provide connectivity to resources such as storage, compute, Layer 2 and Layer 3 (bridged and routed) connectivity, virtual machine hypervisors, Layer 4 to Layer 7 devices, and so on. If a tenant requires interface configurations other than those provided in the default link, Cisco Discovery Protocol (CDP), Link Layer Discovery Protocol (LLDP), Link Aggregation Control Protocol (LACP), or Spanning Tree Protocol (STP), LISP (Locator Identity Separation Protocol) an administrator can configure access policies to enable such configurations on the access ports of Leafs 104.

Node 206 can contain fabric policies that govern the operation of the switch fabric ports, including such functions as Network Time Protocol (NTP) server synchronization, Intermediate System-to-Intermediate System Protocol (IS-IS), Border Gateway Protocol (BGP) route reflectors, Domain Name System (DNS) and so on. The fabric MO contains objects such as power supplies, fans, chassis, and so on.

Node 208

Node 208 can contain VM domains that group VM controllers with similar networking policy requirements. VM controllers can share virtual space (e.g., VLAN or VXLAN space) and application EPGs. Controllers 116 communicate with the VM controller to publish network configurations such as port groups that are then applied to the virtual workloads.

Node 210

Node 210 can contain Layer 4 to Layer 7 service integration life cycle automation framework that enables the system to dynamically respond when a service comes online or goes offline. Policies can provide service device package and inventory management functions.

Node 212

Node 212 can contain access, authentication, and accounting (AAA) policies that govern user privileges, roles, and security domains of Fabric 120.

The hierarchical policy model can fit well with an API, such as a REST API interface. When invoked, the API can read from or write to objects in the MIT. URLs can map directly into distinguished names that identify objects in the MIT. Data in the MIT can be described as a self-contained structured tree text document encoded in XML or JSON, for example.

FIG. 2B illustrates an example object model 220 for a tenant portion of MIM 200. As previously noted, a tenant is a logical container for application policies that enable an administrator to exercise domain-based access control. A tenant thus represents a unit of isolation from a policy perspective, but it does not necessarily represent a private network. Tenants can represent a customer in a service provider setting, an organization or domain in an enterprise setting, or just a convenient grouping of policies. Moreover, tenants can be isolated from one another or can share resources.

Tenant portion 204A of MIM 200 can include various entities, and the entities in Tenant Portion 204A can inherit policies from parent entities. Non-limiting examples of entities in Tenant Portion 204A can include Filters 240, Contracts 236, Outside Networks 222, Bridge Domains 230, VRF Instances 234, and Application Profiles 224.

Bridge Domains 230 can include Subnets 232. Contracts 236 can include Subjects 238. Application Profiles 224 can contain one or more EPGs 226. Some applications can contain multiple components. For example, an e-commerce application could require a web server, a database server, data located in a storage area network, and access to outside resources that enable financial transactions. Application Profile 224 contains as many (or as few) EPGs as necessary that are logically related to providing the capabilities of an application.

EPG 226 can be organized in various ways, such as based on the application they provide, the function they provide (such as infrastructure), where they are in the structure of the data center (such as DMZ), or whatever organizing principle that a fabric or tenant administrator chooses to use.

EPGs in the fabric can contain various types of EPGs, such as application EPGs, Layer 2 external outside network instance EPGs, Layer 3 external outside network instance EPGs, management EPGs for out-of-band or in-band access, etc. EPGs 226 can also contain Attributes 228, such as encapsulation-based EPGs, IP-based EPGs, or MAC-based EPGs.

As previously mentioned, EPGs can contain endpoints (e.g., EPs 122) that have common characteristics or attributes, such as common policy requirements (e.g., security, virtual machine mobility (VMM), QoS, or Layer 4 to Layer 7 services). Rather than configure and manage endpoints individually, they can be placed in an EPG and managed as a group.

Policies apply to EPGs, including the endpoints they contain. An EPG can be statically configured by an administrator in Controllers 116, or dynamically configured by an automated system such as VCENTER or OPENSTACK.

To activate tenant policies in Tenant Portion 204A, fabric access policies should be configured and associated with tenant policies. Access policies enable an administrator to configure other network configurations, such as port channels and virtual port channels, protocols such as LLDP, CDP, or LACP, and features such as monitoring or diagnostics.

FIG. 2C illustrates an example Association 260 of tenant entities and access entities in MIM 200. Policy Universe 202 contains Tenant Portion 204A and Access Portion 206A. Thus, Tenant Portion 204A and Access Portion 206A are associated through Policy Universe 202.

Access Portion 206A can contain fabric and infrastructure access policies. Typically, in a policy model, EPGs are coupled with VLANs. For traffic to flow, an EPG is deployed on a leaf port with a VLAN in a physical, VMM, L2 out, L3 out, or Fiber Channel domain, for example.

Access Portion 206A thus contains Domain Profile 236 which can define a physical, VMM, L2 out, L3 out, or Fiber Channel domain, for example, to be associated to the EPGs. Domain Profile 236 contains VLAN Instance Profile 238 (e.g., VLAN pool) and Attacheable Access Entity Profile (AEP) 240, which are associated directly with application EPGs. The AEP 240 deploys the associated application EPGs to the ports to which it is attached, and automates the task of assigning VLANs. While a large data center can have thousands of active VMs provisioned on hundreds of VLANs, Fabric 120 can automatically assign VLAN IDs from VLAN pools. This saves time compared with trunking down VLANs in a traditional data center.

FIG. 2D illustrates a schematic diagram of example models for implementing MIM 200. The network assurance models can include L_Model 270A (Logical Model), LR_Model 270B (Logical Rendered Model or Logical Runtime Model), Li_Model 272 (Logical Model for i), Ci_Model 274 (Concrete model for i), and Hi_Model 276 (Hardware model or TCAM Model for i).

L_Model 270A is the logical representation of the objects and their relationships in MIM 200. L_Model 270A can be generated by Controllers 116 based on configurations entered in Controllers 116 for the network, and thus represents the configurations of the network at Controllers 116. This is the declaration of the “end-state” expression that is desired when the elements of the network entities (e.g., applications) are connected and Fabric 120 is provisioned by Controllers 116. In other words, because L_Model 270A represents the configurations entered in Controllers 116, including the objects and relationships in MIM 200, it can also reflect the “intent” of the administrator: how the administrator wants the network and network elements to behave.

LR_Model 270B is the abstract model expression that Controllers 116 (e.g., APICs in ACI) resolve from L_Model 270A. LR_Model 270B can thus provide the elemental configuration components that would be delivered to the physical infrastructure (e.g., Fabric 120) to execute one or more policies. For example, LR_Model 270B can be delivered to Leafs 104 in Fabric 120 to configure Leafs 104 for communication with attached Endpoints 122.

Li_Model 272 is a switch-level or switch-specific model obtained from Logical Model 270A and/or Resolved Model 270B. For example, Li_Model 272 can represent the portion of L_Model 270A and/or LR_Model 270B pertaining to a specific switch or router i. To illustrate, Li_Model 272 L₁ can represent the portion of L_Model 270A and/or LR_Model 270B pertaining to Leaf 1 (104). Thus, Li_Model 272 can be generated from L_Model 270A and/or LR_Model 270B for one or more switch or routers (e.g., Leafs 104 and/or Spines 102) on Fabric 120.

Ci_Model 274 is the actual in-state configuration at the individual fabric member i (e.g., switch i). In other words, Ci_Model 274 is a switch-level or switch-specific model that is based on Li_Model 272. For example, Controllers 116 can deliver Li_Model 272 to Leaf 1 (104). Leaf 1 (104) can take Li_Model 272, which can be specific to Leaf 1 (104), and render the policies in Li_Model 272 into a concrete model, Ci_Model 274, that runs on Leaf 1 (104). Leaf 1 (104) can render Li_Model 272 via the OS on Leaf 1 (104), for example. Thus, Ci_Model 274 can be analogous to compiled software, as it is the form of Li_Model 272 that the switch OS at Leaf 1 (104) can execute.

Hi_Model 276 is also a switch-level or switch-specific model for switch i, but is based on Ci_Model 274 for switch i. Hi_Model 276 is the actual configuration (e.g., rules) stored or rendered on the hardware or memory (e.g., TCAM memory) at the individual fabric member i (e.g., switch i). For example, Hi_Model 276 can represent the configurations (e.g., rules) which Leaf 1 (104) stores or renders on the hardware (e.g., TCAM memory) of Leaf 1 (104) based on Ci_Model 274 at Leaf 1 (104). The switch OS at Leaf 1 (104) can render or execute Ci_Model 274, and Leaf 1 (104) can store or render the configurations from Ci_Model in storage, such as the memory or TCAM at Leaf 1 (104). The configurations from Hi_Model 276 stored or rendered by Leaf 1 (104) represent the configurations that will be implemented by Leaf 1 (104) when processing traffic.

While Models 272, 274, 276 are shown as device-specific models, similar models can be generated or aggregated for a collection of fabric members (e.g., Leafs 104 and/or Spines 102) in Fabric 120. When combined, device-specific models, such as Model 272, Model 274, and/or Model 276, can provide a representation of Fabric 120 that extends beyond a particular device. For example, in some cases, Li_Model 272, Ci_Model 272, and/or Hi Model 272 associated with some or all individual fabric members (e.g., Leafs 104 and Spines 102) can be combined or aggregated to generate one or more aggregated models based on the individual fabric members.

As referenced herein, the terms H Model, T Model, and TCAM Model can be used interchangeably to refer to a hardware model, such as Hi_Model 276. For example, Ti Model, Hi Model and TCAMi Model may be used interchangeably to refer to Hi_Model 276.

Models 270A, 270B, 272, 274, 276 can provide representations of various aspects of the network or various configuration stages for MIM 200. For example, one or more of Models 270A, 270B, 272, 274, 276 can be used to generate Underlay Model 278 representing one or more aspects of Fabric 120 (e.g., underlay topology, routing, etc.), Overlay Model 280 representing one or more aspects of the overlay or logical segment(s) of Network Environment 100 (e.g., COOP, MPBGP, tenants, VRFs, VLANs, VXLANs, virtual applications, VMs, hypervisors, virtual switching, etc.), Tenant Model 282 representing one or more aspects of Tenant portion 204A in MIM 200 (e.g., security, forwarding, service chaining, QoS, VRFs, BDs, Contracts, Filters, EPGs, subnets, etc.), Resources Model 284 representing one or more resources in Network Environment 100 (e.g., storage, computing, VMs, port channels, physical elements, etc.), etc.

In general, L_Model 270A can be the high-level expression of what exists in the LR_Model 270B, which should be present on the concrete devices as Ci_Model 274 and Hi_Model 276 expression. If there is any gap between the models, there may be inconsistent configurations or problems.

FIG. 3A illustrates a diagram of an example Assurance Appliance 300 for network assurance. In this example, Assurance Appliance 300 can include k VMs 110 operating in cluster mode. VMs are used in this example for explanation purposes. However, it should be understood that other configurations are also contemplated herein, such as use of containers, bare metal devices, Endpoints 122, or any other physical or logical systems. Moreover, while FIG. 3A illustrates a cluster mode configuration, other configurations are also contemplated herein, such as a single mode configuration (e.g., single VM, container, or server) or a service chain for example.

Assurance Appliance 300 can run on one or more Servers 106, VMs 110, Hypervisors 108, EPs 122, Leafs 104, Controllers 116, or any other system or resource. For example, Assurance Appliance 300 can be a logical service or application running on one or more VMs 110 in Network Environment 100.

The Assurance Appliance 300 can include Data Framework 308, which can be based on, for example, APACHE APEX and HADOOP. In some cases, assurance checks can be written as individual operators that reside in Data Framework 308. This enables a natively horizontal scale-out architecture that can scale to arbitrary number of switches in Fabric 120 (e.g., ACI fabric).

Assurance Appliance 300 can poll Fabric 120 at a configurable periodicity (e.g., an epoch). The analysis workflow can be setup as a DAG (Directed Acyclic Graph) of Operators 310, where data flows from one operator to another and eventually results are generated and persisted to Database 302 for each interval (e.g., each epoch).

The north-tier implements API Server (e.g., APACHE Tomcat and Spring framework) 304 and Web Server 306. A graphical user interface (GUI) interacts via the APIs exposed to the customer. These APIs can also be used by the customer to collect data from Assurance Appliance 300 for further integration into other tools.

Operators 310 in Data Framework 308 (e.g., APEX/Hadoop) can together support assurance operations. Below are non-limiting examples of assurance operations that can be performed by Assurance Appliance 300 via Operators 310.

Security Policy Adherence

Assurance Appliance 300 can check to make sure the configurations or specification from L_Model 270A, which may reflect the user's intent for the network, including for example the security policies and customer-configured contracts, are correctly implemented and/or rendered in Li_Model 272, Ci_Model 274, and Hi_Model 276, and thus properly implemented and rendered by the fabric members (e.g., Leafs 104), and report any errors, contract violations, or irregularities found.

Static Policy Analysis

Assurance Appliance 300 can check for issues in the specification of the user's intent or intents (e.g., identify contradictory or conflicting policies in L_Model 270A).

TCAM Utilization

TCAM is a scarce resource in the fabric (e.g., Fabric 120). However, Assurance Appliance 300 can analyze the TCAM utilization by the network data (e.g., Longest Prefix Match (LPM) tables, routing tables, VLAN tables, BGP updates, etc.), Contracts, Logical Groups 118 (e.g., EPGs), Tenants, Spines 102, Leafs 104, and other dimensions in Network Environment 100 and/or objects in MIM 200, to provide a network operator or user visibility into the utilization of this scarce resource. This can greatly help for planning and other optimization purposes.

Endpoint Checks

Assurance Appliance 300 can validate that the fabric (e.g. fabric 120) has no inconsistencies in the Endpoint information registered (e.g., two leafs announcing the same endpoint, duplicate subnets, etc.), among other such checks.

Tenant Routing Checks

Assurance Appliance 300 can validate that BDs, VRFs, subnets (both internal and external), VLANs, contracts, filters, applications, EPGs, etc., are correctly programmed.

Infrastructure Routing

Assurance Appliance 300 can validate that infrastructure routing (e.g., IS-IS protocol) has no convergence issues leading to black holes, loops, flaps, and other problems.

MP-BGP Route Reflection Checks

The network fabric (e.g., Fabric 120) can interface with other external networks and provide connectivity to them via one or more protocols, such as Border Gateway Protocol (BGP), Open Shortest Path First (OSPF), etc. The learned routes are advertised within the network fabric via, for example, MP-BGP. These checks can ensure that a route reflection service via, for example, MP-BGP (e.g., from Border Leaf) does not have health issues.

Logical Lint and Real-Time Change Analysis

Assurance Appliance 300 can validate rules in the specification of the network (e.g., L_Model 270A) are complete and do not have inconsistencies or other problems. MOs in the MIM 200 can be checked by Assurance Appliance 300 through syntactic and semantic checks performed on L_Model 270A and/or the associated configurations of the MOs in MIM 200. Assurance Appliance 300 can also verify that unnecessary, stale, unused or redundant configurations, such as contracts, are removed.

FIG. 3B illustrates an architectural diagram of an example system 350 for network assurance. In some cases, system 350 can correspond to the DAG of Operators 310 previously discussed with respect to FIG. 3A In this example, Topology Explorer 312 communicates with Controllers 116 (e.g., APIC controllers) in order to discover or otherwise construct a comprehensive topological view of Fabric 120 (e.g., Spines 102, Leafs 104, Controllers 116, Endpoints 122, and any other components as well as their interconnections). While various architectural components are represented in a singular, boxed fashion, it is understood that a given architectural component, such as Topology Explorer 312, can correspond to one or more individual Operators 310 and may include one or more nodes or endpoints, such as one or more servers, VMs, containers, applications, service functions (e.g., functions in a service chain or virtualized network function), etc.

Topology Explorer 312 is configured to discover nodes in Fabric 120, such as Controllers 116, Leafs 104, Spines 102, etc. Topology Explorer 312 can additionally detect a majority election performed amongst Controllers 116, and determine whether a quorum exists amongst Controllers 116. If no quorum or majority exists, Topology Explorer 312 can trigger an event and alert a user that a configuration or other error exists amongst Controllers 116 that is preventing a quorum or majority from being reached. Topology Explorer 312 can detect Leafs 104 and Spines 102 that are part of Fabric 120 and publish their corresponding out-of-band management network addresses (e.g., IP addresses) to downstream services. This can be part of the topological view that is published to the downstream services at the conclusion of Topology Explorer's 312 discovery epoch (e.g., 5 minutes, or some other specified interval).

Unified Collector 314 can receive the topological view from Topology Explorer 312 and use the topology information to collect information for network assurance from Fabric 120. Such information can include L_Model 270A and/or LR_Model 270B from Controllers 116, switch software configurations (e.g., Ci_Model 274) from Leafs 104 and/or Spines 102, hardware configurations (e.g., Hi_Model 276) from Leafs 104 and/or Spines 102, etc. Unified Collector 314 can collect Ci_Model 274 and Hi_Model 276 from individual fabric members (e.g., Leafs 104 and Spines 102).

Unified Collector 314 can poll the devices that Topology Explorer 312 discovers in order to collect data from Fabric 120 (e.g., from the constituent members of the fabric). Unified Collector 314 can collect the data using interfaces exposed by Controller 116 and/or switch software (e.g., switch OS), including, for example, a Representation State Transfer (REST) Interface and a Secure Shell (SSH) Interface.

In some cases, Unified Collector 314 collects L_Model 270A, LR_Model 270B, and/or Ci_Model 274 via a REST API, and the hardware information (e.g., configurations, tables, fabric card information, rules, routes, etc.) via SSH using utilities provided by the switch software, such as virtual shell (VSH or VSHELL) for accessing the switch command-line interface (CLI) or VSH_LC shell for accessing runtime state of the line card.

Unified Collector 314 can poll other information from Controllers 116, including: topology information, tenant forwarding/routing information, tenant security policies, contracts, interface policies, physical domain or VMM domain information, OOB (out-of-band) management IP's of nodes in the fabric, etc.

Unified Collector 314 can also poll other information from Leafs 104 and Spines 102, such as: Ci Models 274 for VLANs, BDs, security policies, Link Layer Discovery Protocol (LLDP) connectivity information of Leafs 104 and/or Spines 102, endpoint information from EPM/COOP, fabric card information from Spines 102, routing information base (RIB) tables, forwarding information base (FIB) tables from Leafs 104 and/or Spines 102, security group hardware tables (e.g., TCAM tables) from switches, etc.

Assurance Appliance 300 can run one or more instances of Unified Collector 314. For example, Assurance Appliance 300 can run one, two, three, or more instances of Unified Collector 314. The task of data collecting for each node in the topology (e.g., Fabric 120 including Spines 102, Leafs 104, Controllers 116, etc.) can be sharded or load balanced, to a unique instance of Unified Collector 314. Data collection across the nodes can thus be performed in parallel by one or more instances of Unified Collector 314. Within a given node, commands and data collection can be executed serially. Assurance Appliance 300 can control the number of threads used by each instance of Unified Collector 314 to poll data from Fabric 120.

Data collected by Unified Collector 314 can be compressed and sent to downstream services. In some examples, Unified Collector 314 can collect data in an online fashion or real-time fashion, and send the data downstream, as it is collected, for further analysis. In some examples, Unified Collector 314 can collect data in an offline fashion, and compile the data for later analysis or transmission.

Assurance Appliance 300 can contact Controllers 116, Spines 102, Leafs 104, and other nodes to collect various types of data. In some scenarios, Assurance Appliance 300 may experience a failure (e.g., connectivity problem, hardware or software error, etc.) that prevents it from being able to collect data for a period of time. Assurance Appliance 300 can handle such failures seamlessly, and generate events based on such failures.

Switch Logical Policy Generator 316 can receive L_Model 270A and/or LR_Model 270B from Unified Collector 314 and calculate Li_Model 272 for each network device i (e.g., switch i) in Fabric 120. For example, Switch Logical Policy Generator 316 can receive L_Model 270A and/or LR_Model 270B and generate Li_Model 272 by projecting a logical model for each individual node i (e.g., Spines 102 and/or Leafs 104) in Fabric 120. Switch Logical Policy Generator 316 can generate Li_Model 272 for each switch in Fabric 120, thus creating a switch logical model based on L_Model 270A for each switch.

Switch Logical Configuration Generator 316 can also perform change analysis and generate lint events or records for problems discovered in L_Model 270A and/or LR_Model 270B. The lint events or records can be used to generate alerts for a user or network operator.

Policy Operator 318 can receive Ci_Model 274 and Hi_Model 276 for each switch from Unified Collector 314, and Li_Model 272 for each switch from Switch Logical Policy Generator 316, and perform assurance checks and analysis (e.g., security adherence checks, TCAM utilization analysis, etc.) based on Ci_Model 274, Hi_Model 276, and Li_Model 272. Policy Operator 318 can perform assurance checks on a switch-by-switch basis by comparing one or more of the models.

Returning to Unified Collector 314, Unified Collector 314 can also send L_Model 270A and/or LR_Model 270B to Routing Policy Parser 320, and Ci_Model 274 and Hi_Model 276 to Routing Parser 326.

Routing Policy Parser 320 can receive L_Model 270A and/or LR_Model 270B and parse the model(s) for information that may be relevant to downstream operators, such as Endpoint Checker 322 and Tenant Routing Checker 324. Similarly, Routing Parser 326 can receive Ci_Model 274 and Hi_Model 276 and parse each model for information for downstream operators, Endpoint Checker 322 and Tenant Routing Checker 324.

After Ci_Model 274, Hi_Model 276, L_Model 270A and/or LR_Model 270B are parsed, Routing Policy Parser 320 and/or Routing Parser 326 can send cleaned-up protocol buffers (Proto Buffs) to the downstream operators, Endpoint Checker 322 and Tenant Routing Checker 324. Endpoint Checker 322 can then generate events related to Endpoint violations, such as duplicate IPs, APIPA, etc., and Tenant Routing Checker 324 can generate events related to the deployment of BDs, VRFs, subnets, routing table prefixes, etc.

FIG. 3C illustrates a schematic diagram of an example system for static policy analysis in a network (e.g., Network Environment 100). Static Policy Analyzer 360 can perform assurance checks to detect configuration violations, logical lint events, contradictory or conflicting policies, unused contracts, incomplete configurations, etc. Static Policy Analyzer 360 can check the specification of the user's intent or intents in L_Model 270A to determine if any configurations in Controllers 116 are inconsistent with the specification of the user's intent or intents.

Static Policy Analyzer 360 can include one or more of the Operators 310 executed or hosted in Assurance Appliance 300. However, in other configurations, Static Policy Analyzer 360 can run one or more operators or engines that are separate from Operators 310 and/or Assurance Appliance 300. For example, Static Policy Analyzer 360 can be a VM, a cluster of VMs, or a collection of endpoints in a service function chain.

Static Policy Analyzer 360 can receive as input L_Model 270A from Logical Model Collection Process 366 and Rules 368 defined for each feature (e.g., object) in L_Model 270A. Rules 368 can be based on objects, relationships, definitions, configurations, and any other features in MIM 200. Rules 368 can specify conditions, relationships, parameters, and/or any other information for identifying configuration violations or issues.

Moreover, Rules 368 can include information for identifying syntactic violations or issues. For example, Rules 368 can include one or more rules for performing syntactic checks. Syntactic checks can verify that the configuration of L_Model 270A is complete, and can help identify configurations or rules that are not being used. Syntactic checks can also verify that the configurations in the hierarchical MIM 200 are complete (have been defined) and identify any configurations that are defined but not used. To illustrate, Rules 368 can specify that every tenant in L_Model 270A should have a context configured; every contract in L_Model 270A should specify a provider EPG and a consumer EPG; every contract in L_Model 270A should specify a subject, filter, and/or port; etc.

Rules 368 can also include rules for performing semantic checks and identifying semantic violations or issues. Semantic checks can check conflicting rules or configurations. For example, Rule1 and Rule2 can have aliasing issues, Rule1 can be more specific than Rule2 and thereby create conflicts/issues, etc. Rules 368 can define conditions which may result in aliased rules, conflicting rules, etc. To illustrate, Rules 368 can specify that an allow policy for a specific communication between two objects can conflict with a deny policy for the same communication between two objects if they allow policy has a higher priority than the deny policy, or a rule for an object renders another rule unnecessary.

Static Policy Analyzer 360 can apply Rules 368 to L_Model 270A to check configurations in L_Model 270A and output Configuration Violation Events 370 (e.g., alerts, logs, notifications, etc.) based on any issues detected. Configuration Violation Events 370 can include semantic or semantic problems, such as incomplete configurations, conflicting configurations, aliased rules, unused configurations, errors, policy violations, misconfigured objects, incomplete configurations, incorrect contract scopes, improper object relationships, etc.

In some cases, Static Policy Analyzer 360 can iteratively traverse each node in a tree generated based on L_Model 270A and/or MIM 200, and apply Rules 368 at each node in the tree to determine if any nodes yield a violation (e.g., incomplete configuration, improper configuration, unused configuration, etc.). Static Policy Analyzer 360 can output Configuration Violation Events 370 when it detects any violations.

FIG. 4 illustrates a flowchart for an example network assurance method. The method shown in FIG. 4 is provided by way of example, as there are a variety of ways to carry out the method. Additionally, while the example method is illustrated with a particular order of blocks, those of ordinary skill in the art will appreciate that FIG. 4 and the blocks shown therein can be executed in any order and can include fewer or more blocks than illustrated.

Each block shown in FIG. 4 represents one or more steps, processes, methods or routines in the method. For the sake of clarity and explanation purposes, the blocks in FIG. 4 are described with reference to Assurance Appliance 300, Models 270A-B, 272, 274, 276, and Network Environment 100, as shown in FIGS. 1A-B, 2D, and 3A.

At step 400, Assurance Appliance 300 can collect data and obtain models associated with Network Environment 100. The models can include Models 270A-B, 272, 274, 276. The data can include fabric data (e.g., topology, switch, interface policies, application policies, EPGs, etc.), network configurations (e.g., BDs, VRFs, L2 Outs, L3 Outs, protocol configurations, etc.), security configurations (e.g., contracts, filters, etc.), service chaining configurations, routing configurations, and so forth. Other information collected or obtained can include, for example, network data (e.g., RIB/FIB, VLAN, MAC, ISIS, DB, BGP, OSPF, ARP, VPC, LLDP, MTU, QoS, etc.), rules and tables (e.g., TCAM rules, ECMP tables, etc.), endpoint dynamics (e.g., EPM, COOP EP DB, etc.), statistics (e.g., TCAM rule hits, interface counters, bandwidth, etc.).

At step 402, Assurance Appliance 300 can analyze and model the received data and models. For example, Assurance Appliance 300 can perform formal modeling and analysis, which can involve determining equivalency between models, including configurations, policies, etc.

At step 404, Assurance Appliance 300 can generate one or more smart events. Assurance Appliance 300 can generate smart events using deep object hierarchy for detailed analysis, such as Tenants, switches, VRFs, rules, filters, routes, prefixes, ports, contracts, subjects, etc.

At step 406, Assurance Appliance 300 can visualize the smart events, analysis and/or models. Assurance Appliance 300 can display problems and alerts for analysis and debugging, in a user-friendly GUI.

In a network environment, sensors can be implemented at various devices or elements in the network to collect data from different locations. In particular the sensors can be implemented, as discussed previously, through APIs provided by network elements and used to query the network elements for the data. The collected data from the sensors can be analyzed to monitor and troubleshoot the network. The data collected from the sensors can provide valuable details about the status, security, or performance of the network, as well as any network elements. Information about the sensors can also help interpret the data from the sensors, in order to infer or ascertain additional details from the collected data. For example, collected data can be used to model behavior and configurations within a network fabric in order to assure the network.

SDNs have been developed in order to improve performance in networks and provide greater control in managing networks. SDNs can decouple network control and forwarding functions to create programmable network control. In turn, this can abstract an underlying network infrastructure from applications and network services. This can allow for easy control and configuring of network environments by network administrators.

Sensors and network tools can be utilized in SDNs to provide assurance in the SDNs. Specifically, sensors can be implemented in an SDN to gather data for the SDN and network tools can model operation and behaviors of the SDN based on data gathered by the sensors. Subsequently, events can be generated for the SDN using the gathered data and models in order to provide assurance in the SDN. Such sensors and network tools can provide assurance on a per-SDN basis. Specifically, such sensors and network tools can provide assurance for a network in a specific network domain without respect to communications and interactions between the network and other networks in different network domains. This is problematic, as network traffic often times originates from one network domain and extends into another network in a different network domain. However, as assurance is only provided on a per-network domain basis, the network traffic is only assured with respect to a specific network that a portion of the network traffic passes through. More specifically, the network traffic is not assured across multiple networks, e.g. SDNs, in multiple domains that the network traffic ultimately spans across. There therefore exist needs for providing assurance across multiple networks, e.g. SDNs, in different network domains.

In order to address these challenges, fabric data for a first network in a network domain can be normalized based on a different network domain of a second network. As discussed previously, fabric data can include applicable data indicating operations of a network fabric to provide network service access (e.g., topology, switch, interface policies, application policies, EPGs, etc.). Subsequently, normalized fabric data of the first network can be correlated with fabric data of the second network to create correlated fabric data across the networks. The correlated fabric data can then be used to provide assurance across the networks in the different domains.

Further, in typical SDNs, policies can be configured which ultimately deploys rules in switches to enforce control on underlying traffic. In particular, policies can be deployed to controllers and/or identity services engines where the policies can be used to deploy rules for controlling underlying traffic. As part of providing assurance, such policies can be modeled to ensure that desired, e.g. intent-based, traffic control is actually being enforced in the SDN. As assurance is provided on a per-network basis, policy checks are performed irrespective of policies that exist in networks in different domains. Specifically, SDNs in different network domains that are communicating with each other can have conflicting or otherwise incompatible policies. In turn, providing assurance on a per-network basis can lead to failures in recognizing the conflicts between the policies. There therefore exist needs for providing policy assurance across multiple networks, e.g. SDNs, in different network domains.

In order to address these challenges fabric data indicating policies in a first network and fabric data indicating policies in a second network can be collected. The first network and the second network can be in different network domains. The policies in the second network can then be normalized with respect to the policies in the first network based on the network domain of the first network. Subsequently, the normalized policies of the second network can be correlated with the policies of the first network to identify whether the policies are compatible. In turn, policy assurance can be provided across the first network and the second network, and corresponding different network domains, based on whether the policies are found to be compatible with each other.

FIG. 5 illustrates an environment 500 for providing cross-domain assurance. The example environment shown in FIG. 5 includes a first network 502, a second network 504, and a cross-domain assurance system 506. The first network 502 and the second network 504 function to provide network service access. Specifically, the first network 502 and the second network 504 can be formed according to an applicable network environment for providing network service access, such as the network environments 100 shown in FIGS. 1A and 1B. In providing network service access the first network 502 and the second network 504 can communicate with each other. Specifically, a traffic flow can originate at or pass through the second network 504 into the first network 502 and vice versa. Further, in communicating with each other, traffic flows passing between the first network 502 and the second network 504 can pass through a firewall.

Both the first network 502 and the second network 504 are in or otherwise form separate network domains. More specifically, both the first network 502 and the second network 504 can be separate SDN networks in separate network domains. The corresponding network domains of the first network 502 and the second network 504 can be different types of network domains. For example, the first network 502 can be an ACI network at a datacenter and the second network 504 can be a campus or digital network architecture (DNA) network of an enterprise. Further in the example, the first network 502 can implement policies within the network through one or more APICs while the second network 504 can implement policies within the network through one or more DNA controllers, e.g. in a DNA center (DNAC), and/or an identity services engine. In another example, the first network 502 can be a DNA network of an enterprise and the second network 504 can be an ACI network at a datacenter. Alternatively, the corresponding network domains of the first network 502 and the second network 504 can be the same type of network domains. For example, both the first network 502 and the second network 504 can be either ACI networks or DNA networks of one or more enterprises.

The cross-domain assurance system 506 functions to provide cross-domain assurance for different networks. More specifically, the cross-domain assurance system 506 functions to provide assurance across the corresponding network domains of the first network 502 and the second network 504. In providing assurance across multiple network domains, the cross-domain assurance system 506 can assure networks based on communications between different networks and corresponding different network domains. More specifically, in providing assurance across multiple network domains, the cross-domain assurance system 506 can assure network communications that occur between different networks in different domains, and potentially with different domain types. This is advantageous as assuring networks across different domains can ensure different networks are actually compatible with each other to provide network service access across the different networks. For example, as will be discussed in greater detail later, the cross-domain assurance system 506 can ensure that policies in different networks are compatible with each other for controlling underlying traffic transmitted within and between the different networks.

In providing cross-domain assurance for different networks, the cross-domain assurance system 506 can collect fabric data from the networks. In particular, the cross-domain assurance system 506 can collect fabric data from the first network 502 and fabric data from the second network 504. In collecting fabric data from networks, the cross-domain assurance system 506 can functions as, or otherwise be implemented as, part of an applicable appliance for providing assurance in a network environment, such as the example assurance appliance 300 discussed herein. The cross-domain assurance system 506 can collect fabric data from an applicable source in a network environment. For example, if a network is an ACI network, then the cross-domain assurance system 506 can collect fabric data, including policies implemented in the ACI network, from one or more APICs in the framework of the ACI network. In another example, if a network is a DNA network, then the cross-domain assurance system 506 can collect fabric data, including policies implemented in the DNA network, from either or both DNA controllers of the DNA network and an identity services engine for the DNA network.

The cross-domain assurance system 506 can normalize fabric data collected from a network with respect to fabric data collected from another network, as part of providing cross-domain assurance across the networks. Specifically, the cross-domain assurance system 506 can normalize fabric data collected from the second network 504 with respect to fabric data collected from the first network 502. Alternatively, the cross-domain assurance system 506 can normalize fabric data collected from the first network 502 with respect to fabric data collected from the second network 504. The cross-domain assurance system 506 can normalize fabric data of a first network based on a network domain of a different network. Specifically, the cross-domain assurance system 506 can translate fabric data into a form that is compatible with fabric data gathered from another network, e.g. for purposes of correlating the network data across networks. For example, as will be discussed in greater detail later with respect to network policies, the cross-domain assurance system 506 can translate policies implemented in the second network 104 into a form of policies that can be understood with or otherwise correlated with policies implemented in the first network 102.

Further, the cross-domain assurance system 506 can correlate fabric data of one network with normalized fabric data of another network for purposes of providing assurance across the networks. Specifically, the cross-domain assurance system 506 can correlate normalized fabric data of the second network 504 with fabric data of the first network 502 for purposes of providing assurance across the networks. Alternatively, the cross-domain assurance system 506 can correlated normalized fabric data of the first network 502 with fabric data of the second network 504 for purposes of providing assurance across the networks. For example, the cross-domain assurance system 506 can correlate fabric data across networks to determine whether the network are correctly configured to transmit data between each other, e.g. as part of providing assurance across the networks. More specifically, in correlating fabric data across the networks, as will be discussed in greater detail later with respect to policies, the cross-domain assurance system 506 can use the correlated fabric data to provide assurance that the networks can operate together to provide network services according to administrator intent.

The cross-domain assurance system 506 can provide assurance across network domains based on policies implemented in the network domains. Specifically, policies can be implemented in networks and otherwise defined based on network types of networks in which the policies are implemented. Subsequently, the cross-domain assurance system 506 can provide assurance across networks based on policies specific to the networks. For example, a policy can be defined based on communications with one or more endpoints and endpoint groups in an ACI network. Subsequently, the cross-domain assurance system 506 can provide assurance across network domains based on the one or more endpoints and endpoint groups in the ACI network. In another example, a policy can be defined based on communications with one or more security groups in a DNA network. More specifically, fabric data for a DNA network can include policies and associated security groups, e.g. security group tags, associated with the policies. Security groups can include one or more users and be formed based on user types and/or device types. For example, security group can be defined to include faculty members in a campus network set up as a DNA network. Subsequently, the cross-domain assurance system 506 can provide assurance across network domains based on the one or more security groups in the DNA network. Specifically, the cross-domain assurance system 506 can guarantee or determine that networks are behaving as intended from a perspective across the networks, as part of providing cross-domain assurance. For example, the cross-domain assurance system 506 can ensure that operating in a compatible fashion with each other according to intent of a network administrator.

By providing assurance across network domains based on policies implemented in the network domains, the cross-domain assurance system 506 can ensure that networks are compatible for communicating with each other to provide network service access. Specifically, by providing assurance across network domains based on policies implemented in the network domains, the cross-domain assurance system 506 can ensure that networks have compatible policies to control underlying traffic flow within and between the networks. For example, if a faculty member in a DNA network is allowed access to a grading portal in an ACI network, then the cross-domain assurance system 506 can determine that the policies in the DNA network and the ACI network are compatible to actually allow the faculty member to access the grading portal through the DNA network and the ACI network. Further, the ACI network can actually control access by the faculty member to the grading portal, e.g. by enforcing policies in the ACI network, based on a corresponding IP address of the faculty member which is used by the ACI network to identify the faculty member as a source of traffic.

The cross-domain assurance system 506 can normalize collected fabric data of policies for purposes of assuring policies across multiple network domains. Specifically, the cross-domain assurance system 506 can normalize policies of a first network in a first domain based on a second network in a second domain in order to provide cross-domain assurance between the first and second networks. More specifically, the cross-domain assurance system 506 can normalize policies in the second network 504 into policies for the first network 502 based on a domain of the first network 502. Conversely, the cross-domain assurance system 506 can normalize policies in the first network 502 into policies for the second network 504 based on a domain of the second network 504.

Specifically, if the first network 502 is an ACI network and the second network 504 is a DNA network, then the cross-domain assurance system 506 can translate policies defined for security groups in the second network 504 into policies defined by endpoint groups in the first network 502. For example, policies for the second network 504 can specify students are allowed to communicate with a library portal in the first network 502 but not a grading portal in the first network 502. Subsequently, the cross-domain assurance system 506 can translate the policies in the second network 504 into L3out_student_SGT, which is an endpoint group associated with communications with the “student” security group outside of the ACI fabric in the second network 504. While the example is described with respect to the first network 502 being an ACI network and the second network 504 being a DNA network, the same example can be applied if the first network 502 is a DNA network and the second network 504 is an ACI network and policies for the first network 502 are normalized with respect to the second network 504.

Alternatively, if the first network 502 is a DNA network and the second network 504 is an ACI network, then the cross-domain assurance system 506 can translate policies defined for endpoint groups in the second network 504 into policies defined by security groups in the first network 502. For example, policies for the second network 504 can specify that a library portal is allowed to communicate with students in a student security group in the first network 502. Subsequently, the cross-domain assurance system 506 can translate the policies for the second network into a policy with security group “LibraryPortal_EPG” for the first network 502. While the example is described with respect to the first network 502 being a DNA network and the second network 504 being an ACI network, the same example can be applied if the first network 502 is an ACI network and the second network 504 is a DNA network and policies for the first network 502 are normalized with respect to the second network 504.

In providing assurance across networks in different network domains, the cross-domain assurance system 506 can correlate fabric data indicating policies of different network to provide assurance, e.g. policy assurance, across the networks. Specifically, the cross-domain assurance system 506 can correlate normalized fabric data of policies for one network with fabric data of policies for another network to provide policy assurance across the networks. For example, the cross-domain assurance system 506 can correlate normalized policy fabric data for the second network 504 with policy fabric data for the first network 502 to provide policy assurance across the first network 502 and the second network 504. Alternatively, the cross-domain assurance system 506 can correlate normalized policy fabric data for the first network 502 with policy fabric data for the second network 504 to provide policy assurance across the first network 502 and the second network 504.

In correlating policy fabric data to provide assurance across networks, the cross-domain assurance system 506 can identify whether policies implemented in the networks are compatible with each other, e.g. as part of correlated fabric data. Specifically, the cross-domain assurance system 506 can use normalized fabric data of the second network 504 and fabric data of the first network 502 to identify whether the policies of the second network 504 are equivalent to the policies in the first network 502. Alternatively, the cross-domain assurance system 506 can use normalized fabric data of the first network 502 and fabric data of the second network 504 to identify whether the policies of the first network are equivalent to policies in the second network 504.

In determining whether policies are equivalent, the cross-domain assurance system 506 can determine whether the policies provide the same configurable control of network traffic in corresponding networks, e.g. as part of correlated fabric data. For example, if a policy in the second network 504 allows a teacher security group to communicate with a grading portal, then the cross-domain assurance system 506 can determine that policies in the first network 502 are equivalent to policies in the second network 504, if a policy in the first network 502 allows the teacher security group to communicate with the grading portal. Further in the example, the cross-domain assurance system 506 can translate the policy in the second network 504 of grading<allow>teacher into a policy for the first network 502 of L3out_teacher_SGT<allow>grading. Still further, the cross-domain assurance system 506 can identify whether the corresponding policy of teacher<allow>grading exists in the first network 502 and subsequently identify that equivalent policies exist between the first network 502 and the second network 504 if teacher<allow>grading exists in the first network 502.

The cross-domain assurance system 506 can determine mismatches, e.g. as part of correlated fabric data, in policies between different networks. Specifically, the cross-domain assurance system 506 can identify mismatches between policies as part of determining whether the policies are equivalent. For example, if a policy in the first network 502 allows student access to a grading portal and a policy in the second network 502 does not allow student access the grading portal, then the cross-domain assurance system 506 can determine the policies are mismatched in allowed student access.

In response to determining whether policies are equivalent, the cross-domain assurance system 506 can generate policy mismatch events, e.g. as part of providing assurance across networks. More specifically, if a policy mismatch is identified, then the cross-domain assurance system 506 can generate a policy mismatch event. The policy mismatch event can be used to alert an administrator of policy mismatches across networks. Further, a policy mismatch event can include indicators of actual mismatches between policies and subsequently be used to alert an administrator of the actual mismatches. In turn, the administrator can reconfigure the policies based on the identified mismatches reported to the administrator through the policy mismatch event. In response to a recognized policy mismatch, the cross-domain assurance system 506 A system can provide alerting to operator(s) and administrator(s) of the identity management system and of the network domain(s) with specific corrective actions in each domain to be taken to resolve any consistency issues between policies. Specifically, the cross-domain assurance system 506 can provide insight into exact semantics (e.g. forwarding, policy, etc.) that may be causing communication (or lack thereof) between two or more endpoints in each domain and suggest specific steps to be followed by the operator(s) or administrator(s) of each domain to either permit or restrict traffic flow between these endpoints. The cross-domain assurance system 506 can provide information related to policy mismatches in simple query terms that allow a user to easily digest this information. For example, the cross-domain assurance system 506 can provide the ability for end users to consume this data using simple query terms like ‘Can A talk to B’ [where A is an endpoint in the datacenter domain, B is an endpoint in a different SDN domain] without having to understand, extrapolate and interpret the intricacies of each SDN domain.

The cross-domain assurance system 506 can communicate with an identity access and management database, e.g. as implemented as part of an identity services engine configured to manage a network, e.g. a DNA network. Specifically, the cross-domain assurance system 506 can query the identity access and management database to obtain mappings of endpoint(s) to security group(s). Further, the cross-domain assurance system 506 can use mappings of endpoints to security groups to provide a framework to map business level intent (E.g. PCI servers should not talk to non-PCI endpoints). Specifically, the cross-domain assurance system 506 can use a tagging mechanism to map business level intent by allowing for mappings of operator or administrator defined tags to security group(s) obtained from the identity management platform or a configuration management database (CMDB). [E.g. The assurance system may let the operator define a tag of “PCI servers” for all endpoints in a subnet range (like 10.1.1.0/24) or all security groups with a certain name (like security group name contains “prod_web_”]

Further, in communicating with the identity and access management database, the cross-domain assurance system 506 to ensure data across networks in different domains is consistent. Specifically, the cross-domain assurance system 506 can cross-reference information from the identity management platform with normalized information from both network domains to determine the sanctity of this data across the identity management system and both network domains is consistent. Subsequently, the cross-domain assurance system 506 can use the cross-referenced information to provide assurance, e.g. policy assurance, across the network domains.

FIG. 6 illustrates a flowchart for an example method of providing cross-domain assurance. The method shown in FIG. 6 is provided by way of example, as there are a variety of ways to carry out the method. Additionally, while the example method is illustrated with a particular order of blocks, those of ordinary skill in the art will appreciate that FIG. 6 and the blocks shown therein can be executed in any order and can include fewer or more blocks than illustrated.

Each block shown in FIG. 6 represents one or more steps, processes, methods or routines in the method. For the sake of clarity and explanation purposes, the blocks in FIG. 6 are described with reference to the environment 500, shown in FIG. 5.

At step 600, the cross-domain assurance system 506 collects first fabric data for a first network in a first domain and second fabric data for a second network in a second domain. The fabric data for either or both the first network and the second network can be collected from a controller in an ACI network. Alternatively, the fabric data for either or both the first network and the second network can be collected from either or both a controller and an identity services engine in a DNA network.

At step 602, the cross-domain assurance system 506 normalizes the second fabric data for the second network based on the first network domain to create normalized second fabric data. In particular, policies for the second network can be translated into policies capable of being implemented in the first network as part of normalizing the second fabric data based on the first network domain. For example, if the first network is an ACI network, then policies for the second network can be translated into policies for communicating with one or more endpoints and endpoint groups in the ACI network. In another example, if the first network is a DNA network, then policies for the second network can be translated into policies for communicating with one or more security groups in the DNA network.

At step 604, the cross-domain assurance system 506 correlates the first fabric data with the normalized second fabric data to create correlated fabric data. In particular, the cross-domain assurance system 506 can compare policies in the second network with policies in the first network, using the first fabric data and the normalized second fabric data, to determine whether the policies are compatible with each other. Further, as part of correlating the first fabric data and the second fabric data to create correlated fabric data, the cross-domain assurance system 506 can identify mismatches between policies in the first network and policies in the second network.

At step 606, the cross-domain assurance system 506 provides assurance across the first network and the second network using the correlated fabric data. Specifically, if the correlated fabric data indicates that policies in the first network and policies in the second network are incompatible, then the cross-domain assurance system 506 can generate a policy mismatch event. Subsequently, the policy mismatch event can be used to alert an administrator that policies in the first and second network mismatch. Additionally, the cross-domain assurance system 506 can generate a policy mismatch event including actual mismatches between policies in the first network and policies in the second network as part of providing assurance across the first network and the second network.

At optional step, the cross-domain assurance system 506 can tag endpoints based on policies and subsequently provide assurance across the first and second networks based on the tagged endpoints. Specifically, the cross-domain assurance system 506 can consume business level intent (e.g. PCI servers should not talk to non-PCI users) and glean mappings of PCI, non-PCI endpoints from a policy, posture verification engine. Further, the cross-domain assurance system 506 can tag these endpoints based on user defined policies. Subsequently, the cross-domain assurance system 506 can perform cross-domain co-relation across the identity management system (e.g. Cisco ISE) and various SDN domains (E.g. Datacenter, WAN, Campus) when intent is violated and provide a notification to the operator(s) and administrator(s) of relevant domains based on business level intent being violated.

FIG. 7 shows a screen shot of an interface 700 showing allowed cross-domain access as part of providing cross-domain assurance. In particular the interface 700 shows that a student security group in a DNA network is allowed access to a grading portal in an ACI network but not allowed access to a library portal in the ACI network. A network administrator can use this information to determine that a policy mismatch is occurring. Specifically, the network administrator can determine the ACI network is improperly configured by allowing a student to access the grading portal and not the library portal, e.g. based on prior knowledge that students are allowed to access the library portal but not the grading portal. Accordingly, the network administrator can determine a policy mismatch exists based on this improper ACI configuration and subsequently reconfigure the ACI network.

The disclosure now turns to FIGS. 8 and 9, which illustrate example network devices and computing devices, such as switches, routers, load balancers, client devices, and so forth.

FIG. 8 illustrates an example network device 800 suitable for performing switching, routing, load balancing, and other networking operations. Network device 800 includes a central processing unit (CPU) 804, interfaces 802, and a bus 810 (e.g., a PCI bus). When acting under the control of appropriate software or firmware, the CPU 804 is responsible for executing packet management, error detection, and/or routing functions. The CPU 804 preferably accomplishes all these functions under the control of software including an operating system and any appropriate applications software. CPU 804 may include one or more processors 808, such as a processor from the INTEL X86 family of microprocessors. In some cases, processor 808 can be specially designed hardware for controlling the operations of network device 800. In some cases, a memory 806 (e.g., non-volatile RAM, ROM, etc.) also forms part of CPU 804. However, there are many different ways in which memory could be coupled to the system.

The interfaces 802 are typically provided as modular interface cards (sometimes referred to as “line cards”). Generally, they control the sending and receiving of data packets over the network and sometimes support other peripherals used with the network device 800. Among the interfaces that may be provided are Ethernet interfaces, frame relay interfaces, cable interfaces, DSL interfaces, token ring interfaces, and the like. In addition, various very high-speed interfaces may be provided such as fast token ring interfaces, wireless interfaces, Ethernet interfaces, Gigabit Ethernet interfaces, ATM interfaces, HSSI interfaces, POS interfaces, FDDI interfaces, WIFI interfaces, 3G/4G/5G cellular interfaces, CAN BUS, LoRA, and the like. Generally, these interfaces may include ports appropriate for communication with the appropriate media. In some cases, they may also include an independent processor and, in some instances, volatile RAM. The independent processors may control such communications intensive tasks as packet switching, media control, signal processing, crypto processing, and management. By providing separate processors for the communications intensive tasks, these interfaces allow the master microprocessor 804 to efficiently perform routing computations, network diagnostics, security functions, etc.

Although the system shown in FIG. 8 is one specific network device of the present invention, it is by no means the only network device architecture on which the present invention can be implemented. For example, an architecture having a single processor that handles communications as well as routing computations, etc., is often used. Further, other types of interfaces and media could also be used with the network device 800.

Regardless of the network device's configuration, it may employ one or more memories or memory modules (including memory 806) configured to store program instructions for the general-purpose network operations and mechanisms for roaming, route optimization and routing functions described herein. The program instructions may control the operation of an operating system and/or one or more applications, for example. The memory or memories may also be configured to store tables such as mobility binding, registration, and association tables, etc. Memory 806 could also hold various software containers and virtualized execution environments and data.

The network device 800 can also include an application-specific integrated circuit (ASIC), which can be configured to perform routing and/or switching operations. The ASIC can communicate with other components in the network device 800 via the bus 810, to exchange data and signals and coordinate various types of operations by the network device 800, such as routing, switching, and/or data storage operations, for example.

FIG. 9 illustrates a computing system architecture 900 wherein the components of the system are in electrical communication with each other using a connection 905, such as a bus. Exemplary system 900 includes a processing unit (CPU or processor) 910 and a system connection 905 that couples various system components including the system memory 915, such as read only memory (ROM) 920 and random access memory (RAM) 925, to the processor 910. The system 900 can include a cache of high-speed memory connected directly with, in close proximity to, or integrated as part of the processor 910. The system 900 can copy data from the memory 915 and/or the storage device 930 to the cache 912 for quick access by the processor 910. In this way, the cache can provide a performance boost that avoids processor 910 delays while waiting for data. These and other modules can control or be configured to control the processor 910 to perform various actions. Other system memory 915 may be available for use as well. The memory 915 can include multiple different types of memory with different performance characteristics. The processor 910 can include any general purpose processor and a hardware or software service, such as service 1 932, service 2 934, and service 3 936 stored in storage device 930, configured to control the processor 910 as well as a special-purpose processor where software instructions are incorporated into the actual processor design. The processor 910 may be a completely self-contained computing system, containing multiple cores or processors, a bus, memory controller, cache, etc. A multi-core processor may be symmetric or asymmetric.

To enable user interaction with the computing device 900, an input device 945 can represent any number of input mechanisms, such as a microphone for speech, a touch-sensitive screen for gesture or graphical input, keyboard, mouse, motion input, speech and so forth. An output device 935 can also be one or more of a number of output mechanisms known to those of skill in the art. In some instances, multimodal systems can enable a user to provide multiple types of input to communicate with the computing device 900. The communications interface 940 can generally govern and manage the user input and system output. There is no restriction on operating on any particular hardware arrangement and therefore the basic features here may easily be substituted for improved hardware or firmware arrangements as they are developed.

Storage device 930 is a non-volatile memory and can be a hard disk or other types of computer readable media which can store data that are accessible by a computer, such as magnetic cassettes, flash memory cards, solid state memory devices, digital versatile disks, cartridges, random access memories (RAMs) 925, read only memory (ROM) 920, and hybrids thereof.

The storage device 930 can include services 932, 934, 936 for controlling the processor 910. Other hardware or software modules are contemplated. The storage device 930 can be connected to the system connection 905. In one aspect, a hardware module that performs a particular function can include the software component stored in a computer-readable medium in connection with the necessary hardware components, such as the processor 910, connection 905, output device 935, and so forth, to carry out the function.

For clarity of explanation, in some instances the present technology may be presented as including individual functional blocks including functional blocks comprising devices, device components, steps or routines in a method embodied in software, or combinations of hardware and software.

In some embodiments the computer-readable storage devices, mediums, and memories can include a cable or wireless signal containing a bit stream and the like. However, when mentioned, non-transitory computer-readable storage media expressly exclude media such as energy, carrier signals, electromagnetic waves, and signals per se.

Methods according to the above-described examples can be implemented using computer-executable instructions that are stored or otherwise available from computer readable media. Such instructions can comprise, for example, instructions and data which cause or otherwise configure a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions. Portions of computer resources used can be accessible over a network. The computer executable instructions may be, for example, binaries, intermediate format instructions such as assembly language, firmware, or source code. Examples of computer-readable media that may be used to store instructions, information used, and/or information created during methods according to described examples include magnetic or optical disks, flash memory, USB devices provided with non-volatile memory, networked storage devices, and so on.

Devices implementing methods according to these disclosures can comprise hardware, firmware and/or software, and can take any of a variety of form factors. Typical examples of such form factors include laptops, smart phones, small form factor personal computers, personal digital assistants, rackmount devices, standalone devices, and so on. Functionality described herein also can be embodied in peripherals or add-in cards. Such functionality can also be implemented on a circuit board among different chips or different processes executing in a single device, by way of further example.

The instructions, media for conveying such instructions, computing resources for executing them, and other structures for supporting such computing resources are means for providing the functions described in these disclosures.

Although a variety of examples and other information was used to explain aspects within the scope of the appended claims, no limitation of the claims should be implied based on particular features or arrangements in such examples, as one of ordinary skill would be able to use these examples to derive a wide variety of implementations. Further and although some subject matter may have been described in language specific to examples of structural features and/or method steps, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to these described features or acts. For example, such functionality can be distributed differently or performed in components other than those identified herein. Rather, the described features and steps are disclosed as examples of components of systems and methods within the scope of the appended claims.

Claim language reciting “at least one of” refers to at least one of a set and indicates that one member of the set or multiple members of the set satisfy the claim. For example, claim language reciting “at least one of A and B” means A, B, or A and B. 

What is claimed is:
 1. A method, comprising: collecting fabric data across a plurality of network domains, wherein the fabric data indicates one or more policies implemented in corresponding network domains of the plurality of network domains; translating at least a portion of the fabric data into a form that is compatible with another portion of the fabric data to create translated fabric data; correlating the fabric data across the plurality of network domains based on the translated fabric data to create correlated fabric data across the plurality of network domains; and providing policy assurance across the plurality of network domains by determining whether the one or more policies implemented in corresponding network domains of the plurality of network domains are compatible across the plurality of network domains based on the correlated fabric data.
 2. The method of claim 1, wherein the plurality of network domains includes a first network domain and a second network domain in a same network environment.
 3. The method of claim 1, wherein the plurality of network domains includes a first network domain, a second network domain, and a third network domain the method further comprising: translating either or both first fabric data for the first network domain and second fabric data for the second network domain into a form that is compatible with third fabric data for the third network domain to create the translated fabric data; correlating the first fabric data, the second fabric data, and the third fabric data across the first network domain, the second network domain, and the third network domain based on the translated fabric data to generate the correlated fabric data; and providing the policy assurance across the first network domain, the second network domain, and the third network domain based on the correlated fabric data.
 4. The method of claim 1, wherein at least one of the plurality of network domains is a virtualized network domain.
 5. The method of claim 1, further comprising: comparing policies identified from the translated fabric data across the plurality of network domains; and generating the correlated fabric data across the plurality of network domains based on a comparison of the policies across the plurality of network domains.
 6. The method of claim 5, further comprising: identifying one or more mismatches in the policies across the plurality of network domains; and generating the correlated fabric data across the plurality of network domains based on the one or more mismatches in the policies across the plurality of network domains.
 7. The method of claim 1, wherein the plurality of network domains includes a first network domain and a second network domain and the fabric data indicates first one or more policies implemented in the first network domain, the method further comprising translating the first one or more policies into second one or more policies capable of being implemented in the second network domain to generate the translated fabric data.
 8. The method of claim 7, wherein the first one or more polices are translated into one or more policies for communicating with either or both one or more endpoints and one or more endpoint groups.
 9. The method of claim 7, wherein the first one or more polices are translated into one or more policies for communicating with one or more security groups.
 10. A system comprising: one or more processors; and a computer-readable medium comprising instructions stored therein, which when executed by the one or more processors, cause the one or more processors to: collect fabric data across a plurality of network domains, wherein the fabric data indicates one or more policies implemented in corresponding network domains of the plurality of network domains; translate at least a portion of the fabric data into a form that is compatible with another portion of the fabric data to create translated fabric data; correlate the fabric data across the plurality of network domains based on the translated fabric data to create correlated fabric data across the plurality of network domains; and provide policy assurance across the plurality of network domains by determining whether the one or more policies implemented in corresponding network domains of the plurality of network domains are compatible across the plurality of network domains based on the correlated fabric data.
 11. The system of claim 10, wherein the plurality of network domains includes a first network domain and a second network domain in a same network environment.
 12. The system of claim 10, wherein the plurality of network domains includes a first network domain, a second network domain, and a third network domain and the instructions, which when executed by the one or more processors, further cause the one or more processors to: translate either or both first fabric data for the first network domain and second fabric data for the second network domain into a form that is compatible with third fabric data for the third network domain to create the translated fabric data; correlate the first fabric data, the second fabric data, and the third fabric data across the first network domain, the second network domain, and the third network domain based on the translated fabric data to generate the correlated fabric data; and provide the policy assurance across the first network domain, the second network domain, and the third network domain based on the correlated fabric data.
 13. The system of claim 10, wherein at least one of the plurality of network domains is a virtualized network domain.
 14. The system of claim 10, wherein the instructions, which when executed by the one or more processors, further cause the one or more processors to: compare policies identified from the translated fabric data across the plurality of network domains; and generate the correlated fabric data across the plurality of network domains based on a comparison of the policies across the plurality of network domains.
 15. The system of claim 10, wherein the instructions, which when executed by the one or more processors, further cause the one or more processors to: identify one or more mismatches in the policies across the plurality of network domains; and generate the correlated fabric data across the plurality of network domains based on the one or more mismatches in the policies across the plurality of network domains.
 16. The system of claim 10, wherein the plurality of network domains includes a first network domain and a second network domain and the fabric data indicates first one or more policies implemented in the first network domain and the instructions, which when executed by the one or more processors, further cause the one or more processors to translate the first one or more policies into second one or more policies capable of being implemented in the second network domain to generate the translated fabric data.
 17. The system of claim 16, wherein the first one or more polices are translated into one or more policies for communicating with either or both one or more endpoints and one or more endpoint groups.
 18. The system of claim 16, wherein the first one or more polices are translated into one or more policies for communicating with one or more security groups.
 19. A non-transitory computer-readable storage medium comprising instructions stored therein, which when executed by one or more processors, cause the one or more processors to: collect fabric data across a plurality of network domains, wherein the fabric data indicates one or more policies implemented in corresponding network domains of the plurality of network domains; translate at least a portion of the fabric data into a form that is compatible with another portion of the fabric data to create translated fabric data; correlate the fabric data across the plurality of network domains based on the translated fabric data to create correlated fabric data across the plurality of network domains; and provide policy assurance across the plurality of network domains by determining whether the one or more policies implemented in corresponding network domains of the plurality of network domains are compatible across the plurality of network domains based on the correlated fabric data.
 20. The non-transitory computer-readable storage medium of claim 19, wherein the plurality of network domains includes a first network domain and a second network domain in a same network environment. 